Restrict Armature only for Pose Mode
Yes, this method will disable edit mode of the mesh too.
First put the armature layers into the Protected layers.

To do so, in the Skeleton panel, Ctrl-LMB click on the relevant
button, the layer lock will be enabled.
.. all bones in this layer will not be editable...for all proxies

Here is an example using  Vincent, a free, open source, fully rigged, professional model.

Then save the file.
Then open a new file and File--&gt;Link --&gt;select the .blend file--&gt; Object folder and select the object and its armature
After the object and armature are linked into the scene, select the armature with RMB and press CTRL+ALT+P to make it a proxy object
https://www.youtube.com/watch?v=uaAHA5IQp_g&amp;feature=youtu.be&amp;t=3m16s

If you upload your .blend  I can make an example